package com.kob.matchingsystem.service.impl.utils;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.locks.ReentrantLock;

//匹配系统需要实现多名玩家同时匹配，所以需要实现多线程
@Component
public class MatchingPool extends Thread{

    private static List<Player> players = new ArrayList<>();
    private final ReentrantLock lock = new ReentrantLock();
    private static RestTemplate restTemplate;
    private final static String startGameUrl = "http://127.0.0.1:3000/pk/start/game/";

    @Autowired
    public void setRestTemplate(RestTemplate restTemplate){
        MatchingPool.restTemplate = restTemplate;
    }

    public void addPlayer(Integer userId,Integer rating,Integer botId){
        lock.lock();
        try{
            players.add(new Player(userId,rating,botId,0));
        }finally {
            lock.unlock();
        }
    }

    public void removePlayer(Integer userId){
        lock.lock();
        try{
            ArrayList<Player> newPlayers = new ArrayList<>();
            for (Player player : MatchingPool.players) {
                if(!userId.equals(player.getUserId())){
                    newPlayers.add(player);
                }
            }
            players = newPlayers;
        }finally {
            lock.unlock();
        }
    }

    private void increaseWaitingTime(){//所以当前玩家的等待时间+1
        for (Player player : players) {
            player.setWaitingTime(player.getWaitingTime()+1);
        }
    }

    private boolean checkMatched(Player a,Player b){ //判断两名玩家是否匹配成功
        int ratingDelta = Math.abs(a.getRating() - b.getRating());//a和b的天梯积分差
        int waitingTime = Math.min(a.getWaitingTime(), b.getWaitingTime());
        if(ratingDelta < 30) return true; // 如果两个玩家分差不大，就直接匹配成功
        return ratingDelta <= waitingTime * 10;//如果分差太大，两个玩家就需要等待一段时间
    }

    private void sendResult(Player a,Player b){
        MultiValueMap<String,String> data = new LinkedMultiValueMap<>();
        data.add("a_id",a.getUserId().toString());
        data.add("a_bot_id",a.getBotId().toString());
        data.add("b_id",b.getUserId().toString());
        data.add("b_bot_id",b.getBotId().toString());
        restTemplate.postForObject(startGameUrl,data,String.class);
    }

    private void matchPlayers(){//尝试匹配所有玩家
        boolean[] used = new boolean[players.size()];
        for (int i = 0; i < players.size(); i++) {
            if(used[i]) continue;
            for (int j = i + 1; j < players.size(); j++) {
                if(used[j]) continue;
                Player a = players.get(i);
                Player b = players.get(j);
                if(checkMatched(a,b)){//取出两名玩家，判断是否可以匹配
                    used[i] = used[j] = true;
                    sendResult(a,b);
                    break;
                }
            }
        }
        ArrayList<Player> newPlayers = new ArrayList<>();
        for (int i = 0; i < players.size(); i++) {
            if(!used[i]){
                newPlayers.add(players.get(i));
            }
        }
        players = newPlayers;
    }

    @Override
    public void run() {
        while(true){
            try {
                Thread.sleep(1000);
                lock.lock();
                try {
                    increaseWaitingTime();
                    matchPlayers();
                }finally {
                    lock.unlock();
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
                break;
            }
        }
    }
}
